Sliver for insulating wires



Oct. 20, 1925. 1,557,803

w. E. COOK SLIVER FOR INSULATING WIRES Filed Dec. 12. 1924 INVENTOR W ZWM ATTORNEY Patented Oct. 20, 1925.

WILLIAM n. 0001:, on NEW YORK, N. Y.

8 m ron INsuLA'rINc wnms.

Application filed December 12, 1924. Serial No. 755,376.

To allwhom it may concern:

Be it known that I, WILLIAM E. COOK, a

subject of the King of the United Kingdom of Great Britain and Ireland, residing at St. George, in the borough of Richmond, city of New York, county of Richmond, and State ofNew York, have invented certain new and useful Improvements in 'Slivers for Insulating Wires, of which the following is a specification, reference being had therein to theaccompanying drawings, which form a part thereof.

My invention'relates to sliver for insulating wires, and more articularly to a sliver so formed that the flu ng or bunching of the outer loosely matted fibers of the strip of sliver while it is being drawn from the container and applied to and compacted upon the wire will be avoided and the wire will be capable of resisting longitudinal stresses thereon incidental to its application to a wire.

, Cotton sliver used as the base of the insulating material for conductor wires is a 25 loosely matted'low grade cotton which upon leaving the carding machine has the edges of a sheet folded upon the central longitudinal portion thereof, and thus form a strip of' sliver free from any twisting or material compaction thereof, since it is desirable to preserve the maximum degree of porosity to ensure a thorough saturation of the sliver with an asphaltum or other com osition after it has been compacted upon t e wire. As this sliver is wound upon the wire, it is so loosely matted that in drawing it from the container immediately prior to its application to the wire, there is, by reason of the high speed of operations of the covering machine, a tendencyof the outer fibers to fluff away from the sliver strip and form a bunch .of progressively increasing size until the sliver is so weakened at a point thereof to cause the breakage of the sliver, necessitating the shutting down of a covering machine, and the formation of :1 splice in the covering sliver. This condition may also result in the formation of spots of relatively less po-' rosity in the length of the wire in the event that such flufls or bunches do not cause the breakage of the sliver, but are carried into the compacting die and are compressed sufficiently to pass through this die. Furthertion in bunches of surface flufl' upon the sliver to, an extent which will cause any material variation in the degree of compaction of different portions of the sliver applied to the wire, and will prevent the accumulation of such fluff in a bunch of a size which will so weaken the sliver as to cause its breakage in the manner above referred to. I also preferably provide, in conjunction with said superficial strand, a longitudinally extending strengthening thread, cord or strand, imbedded in the body of the sliver strip, this thread, cord or strand being of sufficient strength to resist the longitudinal stresses to which the sliver strip is subjected when drawing it from the container and winding it upon the conductor WIIG.

While the externally positioned threads,

cords or strands will serve to prevent the weakening and breakage of the sliver as a result of the bunching or balling of the surface fluif, their arrangement is not such as to contribute to the longitudinal strength of the sliver strip so that, particularly with high speed machines, the longitudinally extending thread, cord or strand has been found desirable when the sliver is used upon high speed covering machines.-

The invention consists primarily in sliver for insulating wires embodyin therein a strip of loosely matted fibers iavin at spaced distances, superficially and iongitudinally thereof, strands of sufficient stren h to check the accumulation of surface here in a bunch or ball; and in such other novel features and characteristics as are hereinafter set forth and described, and more particularly pointed out in theclaims hereto appended.

Referring to the drawings,

Fi 1 is a perspective view of a short lengti of sliver strip showing the longitudinal reinforcing thread, cord or strand, and the superficially positioned thread, cord Or strand before the strip has received its final fold; and

Fig. 2 is a similar view illustrating the sliver strip in its final form for use in a covering machine.

Like letters refer to like parts in both of said views.

In the embodiment of the invention shown in the drawings, the sliver insulating for conductor wires is shown as consistin of cotton sliver having its opposite edges olded longitudinall of the strip upon its 'central portion, tiis central portion being shown at a and the turned edges thereof at b and 0 respectively, one of these edges overlapping the other. Between the central portion a and the folded edges bc is a lonitudinally extending thread, cord or strand g, which is thus imbedded in the body of the sliver strip, so as to take up practically all of the strains incidental to drawing the strip from the container in which it is stored, and winding it by the covering machine spirally about the conductor Wire.

.About the strip so folded is a spirally wound thread, cord or strand 6 which is positioned superficially or exteriorly of the strip, first by reason of its being wound about the f0 ded strip as shown in Fig. 1,

and also within the strip as a result of a.

final fold along substantially the. central line of the strip to produce a finished strip as shown in Fig. 2.

By this construction the thread, cord or strand e is held against displacement longitudinally of" the strip and projects across the substantially longitudinally laid fibers thereof at both edges and upon both sides of the strip, portions of this tliread,'cord or strand extending within the final fold of the strip so as to check any tendency of the fluff bem drawn from along this edge fold,

to beneat the superficial or exterior strand. With asliver insulating or covering strip formed as described, as "it is being drawn from the container, as a-result of the rotai tion of this container about the axis of the wire being covered, and the movement of the wire, if byreason'of rubbing action against the edge of the outlet of the container, Or a ainst ides for the strip as it is there rom to the wire, or because of the enmeshment of the fibers of succeeding convolutions with each other while withp in the container, there should be a tendency to pull the surface fibersaway from the rest of the strip, or to lift succeeding convolutions together, as soon as suchflufi' or fiber strikes one of the spaced portions of the thread, cord or strand 6, it will encounter vsufficient resistance to tear this fluff from the body of the strip, or else cause it to be imbedded with portions of the strip immedi ately beyond this thread, cord or strand. This will effectually check any tendency toward the formation of a bunch or ball of sufficient magnitude to result in the thinning or attenuation of the strip to a point where the substantial uniformity in its thicknessor density after it has been applied to the wire will be affected, or will cause the breakage of the strip through the weakening of the already loosely enmeshed fibers. p

The resistance offered to the accumulation of the fluff in the event of several convolutions of the strip being drawn simultaneously toward the outlet of the container will almost invariably result in the breakage of the light bond due to the enmeshment of such surface fibers of succeeding convolutions, and thus prevent the resulting entanglement of differentportions of the strip.

The extra fold positioning spaced portions of the continuous spirally wound strand within, as well as without, the folded strip, is desirable as tending to avoid the formation of a run within this fold, although advantageous results can be secured by using a covering sliver which is not thus folded, but in which the thread, cord or strand e merely passes about the folded stri and not within a fold thereof, as descri ed.

The spacing of the succeedin convolutions of the thread, cord or stran 0 may be varied, this being largely a matter of economy. By spacing. these strands three or four inches apart, however, the difliculties-heretofore encountered by the use of these stri s in high speed machines, due to the balling or bunchmg of the fluff, have been satisfactorily eliminated.

It is not my intention therefore to limit the invention to the recise details shown in the accompanying rawings, it being apparent that such may be varied without departing from the spirit and scope of the invention.

Having described the invention, what I claim as new and desire to have protected by Letters Patent, is Y 1. Sliver for insulating wires embodying therein a strip of loosely matted fibers having at spaced distances longitudinally and superficially thereof, portions of a continuous strand of suflicient strength to check the accumulation of surface fibers into a bunch or ball.

2. Sliver for insulating wires embodying therein a strip of loosely matted fibers, the longitudinal side edges o'f-which are folded upon the central portion thereof, a longitudinally extending strandbetween said side edges and saidcentral portion, said stri having at spaced distances longitudinal y and superficially thereof, portions of I a continuous strand of suflicient strength to check the accumulation of surface fibers into a bunch or ball.

3. Sliver for insulating wires embodying therein a strip of loosel matted fibers having a continuous spira y wound strand of sufficient strength to check the accumulation of surface fibers in a bunch or ball, succeeding convolutions of said spirally wound strand bein at spaced distances longitudinally of said strip and superficially thereof. I

4. Sliver for insulating wires embodying therein a strip of loosely matted fibers, the longitudinal side edges of which are folded upon the central portion thereof, a longitudinally extending strand between said side edges and said central portion, said strip having a continuous splrall wound strand of sufiicient strength to c eck the accumulation of surface bers in a bunch or ball, succeeding convolutions of said spirally wound strand being at spaced distances longitudinally of said stnp and superficially thereof.

5. Sliver for insulating wires embodying therein a strip of loosely matted fibers having the opposite edges thereof folded upon the central portion, a reinforcing strand extending longitudinally between said folded gortions and said central portion, said strip eing folded along substantially the longitudinal center thereof and having a strand of suflicient strength to check the accumulation of surface fibers in a bunch or ball, wound spirally about said strip and within the central longitudinal fold thereof.

In witness whereof I have hereunto affixed my signature this 8th day of December, 1924.

WILLIAM E. -:COOK. 

